The present invention relates to a position stable segmented column penile prosthesis More particularly, the present invention relates to a position stable segmented column penile prosthesis wherein frictional force between adjacent segments retains the penile prosthesis in any position into which it is manipulated.
The causes of male impotence are many and varied. Various approaches to treating impotence have been developed in the past. Penile prostheses have been implanted within the penis to simulate an erectile state. There are several such prostheses known which use hydraulic or mechanical means of creating an artificial erection. The hydraulic devices provide an erect and a non-erect state, but have had reported problems of valve failure or fluid loss, each of which render the prosthesis unusable. An example of a hydraulic prosthesis is U.S. Pat. No. 3,954,102 to Buuck. The prosthesis is controlled by varying the amount of fluid in cylinders within the prosthesis by squeezing an elastomeric bulb through the patient's skin to transfer fluid from a reservoir into cylinders in the prosthesis. Because the reservoir and bulb are positioned outside of the prosthesis within the patient's body, the implantation procedure is quite complex and the extensive tubing required to interconnect the various portions of the system increase the possibility of failure. Other implantable prosthesis incorporating a reservoir pump and valving are shown in U.S. Pat. Nos. 4,369,771 and 4,353,360. As with the Buuck patent, these prostheses systems require pump and valving apparatus to be installed within the prosthesis and require the transfer of fluid from a reservoir into an inflatable portion for operation.
The mechanically operated prostheses are of basically three types. The first type is that of a solid rod of material, either flexible or inflexible. Although these types of prostheses provide adequate erection, in addition to other problems, there is patient discomfort due to the inability to conceal an erection. The second type of mechanical prosthesis device is a solid flexible rod having the added feature of a ductile metal core which provides adequate erection as well as the ability to bend the prosthesis into a concealable position An example of such a prosthesis device is U.S. Pat. No. 3,987,789 to Timm et al. In this patent, a prosthesis including an elongated malleable rod portion housed within a generally tubular physiologically inert plastic body is disclosed. The malleable rod portion enables the prosthesis to be conformed to a variety of shapes by bending or twisting. During intercourse, the prosthesis will maintain the penis in an erectile state and afterwards, the penis may be positioned and maintained by the user in a convenient, comfortable position. The prosthesis of Timm et al. depends upon its malleability to permit moving the prosthesis to a convenient, comfortable position or configuration. The flexibility of the prosthesis is not controllable by the patient. In addition to other problems, this prosthesis device has a limited life due to fatigue of the malleable material caused through normal use.
A third type of mechanical prosthesis device includes an articulated column of segments having a tensioning member and switch. This prosthesis device provides an erect condition or state by the tensioning member creating a force that pushes the segments of the articulated column together The force and the coefficient of friction of the segment material create a frictional force which facilitates maintaining the position of the segments relative to each other. A flaccid state or condition is created by activating a switch which reduces the tension of the tensioning member and so reduces the friction between the segments. With the friction reduced, the articulated column takes on a flaccid state and is readily capable of being concealed in a perfectly natural configuration. Examples of such a mechanical prosthesis device are commonly assigned Pat. Nos. 4,541,420; 4,522,198; 4,519,251, and 4,517,987. Although such a prosthesis device represents an improvement over the existing devices, the prosthesis device does require the presence of the switching element which increases the complexity of the prosthesis. Increasing the complexity of a device generally means an increase in cost and an increase in the probability of mechanical failure.
The present invention solves these and many other problems associated with currently available devices.